Machine for bending sheet metal shapes



Sept. 23, 1941. A RAFTER MACHINE FQR BENDING SHEET METAL SHAPES Filed April 2, 1940 2 Sheets-Sheet 1 I l VENTOR BY ATTORNEY Sept. 23,1941. A. RAFTE Y -2.?-'=.6.908

MACHINE FOR BENDING SHEET METAL SHAPES Filed April 2, 1940 2 Sheets-Sheet 2 YT g INVEETOR g zaw ATTORNEY Patented Sept. 23, 194i STTES PATENT OFFICE MACHINE FOR BENDING SHEET METAL SHAPES Rafter, Jr.

Application April 2, 1940, Serial No. 327,465

7 Claims.

ture has been found objectionable in that the adjusting screw is subjected to bending when the pitman is in action.

It is, therefore, an object of this invention to provide in a machine of the class described, beams pivotally mounted near the upper end of the housing, which at the front ends thereof support means for reciprocating the ram, and means at the rear ends thereof and remote from the ram, to adjustably raise or lower the front ends of the beams to adjust the position of the ram, thereby preventing said means at the rear ends from being subject to the tremendous stresses incidental to a stamping operation, at the same time producing a simple bending machine of relatively light weight, and which occupies an unusually small amount of space for the enormous forces it is intended to exert.

A further object of this invention is the provision of an overhead drive for a machine for bending sheet metal plates into desired shapes, which consists in providing in the side walls of the housing of the machine, near the top thereof, a bearing having pivotally mounted thereon a pair of beams which have at one end thereof a shaft carrying a pitman connected with the ram or hammer of the machine and designed to reciprocate the same. In order to adjust the angular position of said beams around the bearing, thereby adjusting the position of the ram, namely, raising or lowering it, any suitable means are provided at the opposite ends of the beams and remote from the ram, which may consist of worms and worm gears which cause the rotation of an adjusting screw.

These and other advantageous objects, which will later appear, are accomplished by the novel and practical construction and arrangement of parts hereinafter described and exhibited in the accompanying drawings, constituting a material part of this disclosure, and in which:

Fig. 1 is a front elevational view of the machine embodying the invention,

Fig. 2' is a top plan View of the machine,

Fig. 3 is a side elevational view,

Fig 4 is a. side View of a beam used in the machine, and,

Fig. 5 is a sectional view taken on line 5-5 of Fig.4.

Referring to the drawings, the machine is shown to comprise a bed 4 adapted to support a die 5. Secured to the rear of the bed and extending upwardly therefrom are the two sides 6 of a housing. In the upper ends of the sides of the housing are mounted fixed bearings 1 in which is rotatably mounted a drive shaft i5 having fixed to the ends thereof pinions [B in engagement with gears 9 which are adapted to receive power from a drive pulley I1. Instead of mounting the bearings l in the side walls, the bearings can be formed integral therewith.

The structure of each side of the machine is the same, and consequently the description of one side only is hereinafter given.

Referring to Fig. 5, it will be seen that the ends of the bearing I extend beyond the sides of the housing member 6 and rotatably mounted on said bearing 1 are the beam members 88. A shaft 10 is journalled in one end of the beam members 8-8, said shaft carrying an eccentric II which moves in an eccentric strap l8. The shaft ID has fixed thereto a large gear 9. The eccentric strap I8 is integral with a pitman l9 which is connected by any suitable means, for instance, a ball and socket joint I2, to the upper edge of a ram 13, having sliding engagement with' the lfront I3 of the housing, adapted to support die 4.

The beam members 8-8, at the end opposite the shaft H] are provided with rectangular slots 20 on the inner walls thereof, said slots having positioned therein rectangular guide blocks 2| in which are journalled the cylindrical ends 22 of a trunnion nut 23, having in the center thereof a threaded opening 24 which receives a threaded adjusting screw 25, the latter extending above the housing wall 6 and having fixed thereto at its upper end a worm wheel 26 which is in mesh with the worm 21 adapted to be controlled by a hand wheel 28.

In operation, when it is desired to adjust the position of the ram I3, the handle wheel is manipulated to rotate the worm wheel 26, to cause the adjusting screw 25 to act upon the trunnion nut 23 to raise or lower the beam members 8, which causes an adjustment of the ram l3, raising or lowering the same.

From the above description it will be seen that there has been provided a simple and effective structure for adjusting the position of the ram in a machine for bending metal sheets, the adjusting means being remote from the actuating pitmans, and consequently not subjected to the tremendous stresses incidental to a stamping operation. The guide blocks 2| are slidably mounted in the slots 20 lengthwise of the beam members 8, upward and downward movement of the blocks being prevented by contact with the side walls of the beam members 8. The structure above described enables an overhead drive for a machine for bending metal sheets and provides lower head room. Also, a shorter housing is required, using less material which naturally decreases the cost of manufactureof the machine, and increases the sturdiness and eiiiciency of the same.

While there has been described herein specifically a trunnion nut 23 and adjusting screw 25 for adjusting the position of the ram l3, it shouldbe noted that other equivalent adjusting means can be provided remote from'the pitman, without departing from the spirit of this invention.

The foregoing disclosure is to be regarded as descriptive and illustrative only, and not as restrictive or limitative of the invention, of which, obviously, embodiments may be constructed including many modifications, without departing from the spirit and scope of the invention herein set forth and denoted in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patcut,- is:

1. In a bending machine, a housing having a side wall provided with a bearing, a drive shaft journalled in said bearing and having a pinion fixed thereto, a pair of beam members positioned on opposite sides of said side walls and rotatably mounted on said bearing, a ram, a shaft journalled in one end of said beam members and having a gear in mesh with said pinion, said shaft carrying eccentric means for actuating said ram, means on said ram cooperating with said eccentric means and forming a connection between said shaft and said ram and means at the opposite end of said beam members for adjusting the angularpositionof said beam about said bearing to adjust the position of the ram.

2. In a bending machine, a housing having a side wall, a beam pivotallyv mounted near the-upper end of the side Walharam, eccentric means at one end of the beam to reciprocate said ram, means on said ram cooperating with saidec centric means and forming a connection between saidshaft and said ram and means at the other end of the beam to adjustably raise or lower the,

beam to adjust the position of the ram.

3. In a bending machine, a housing having a side wall, a bearing mounted in said side Wall, a

drive shaft journalled in said bearing and having a pinion fixed thereto, a; pair of beam members positioned onopposite sides of i said side Wall .and rotatably mounted on said bearing, a ram, a shaft journalled in one endof said beam members and having a gear fixed thereto in mesh with said pinion, said shaft carrying eccentric means for actuating said ram,meansonsaidramcooperating with said eccentric means and forming a connection between said shaft and said,

ram, said beam members having at the opposite ends thereof guide slots on their inner walls, rectangular guide blocks positioned in said slots, a trunnion nut positioned between the beams and having cylindrical portions journalled in said guide blocks, an adjusting screw passing through said nut, and means to rotate the adjusting screw to cause said trunnion nut to raise or lower said beam members.

4. In a bending machine, a housing having a side wall, a bearing mounted in said side wall and having a drive shaft journalled therein, a beam pivotally mounted on said bearing, a ram, eccentric means at one end of the beam driven by said drive shaft to reciprocate said ram, means on said ram cooperating with said eccentric means and forming a connection between said shaft and said ram and means at the other end of the beam to adjustably raise or lower said beam to adjust the position of the ram.

5. In a bending machine, a housing having a side wall, a bearing mounted in the upper portion of said housing, a drive shaft journalled in said bearing, a beam pivotally mounted on said bearing, a shaft journalled in one end of the beam, means to drive said shaft from the drive shaft, a ram, eccentric means to actuate said ram by the shaft journalled in the beam, means on said ram cooperating with said eccentric means and forming a connection between said shaft and said ram and means carried by the other end of the beam to raise or lower the beam to adjust the position of said ram.

6. In a bending machine, a bed adapted to support a die member, a housing having side walls attached to said bed, bearings mounted insaid side walls, a drive shaft journalled in said bearings and having a pinion fixed thereto, each of said bearings having a pair of beam members rotatably mounted thereon, said beam members being on opposite sides of a side wall of the housing, a shaft rotatably mounted in said beam members'and carrying an eccentric, a gear fixed to said shaft and engaging said pinion, said eccentric moving in an eccentric strap attached to a pitman, a ram connected to the pitman, and means at the opposite ends of the beammembers to rotate said beam members about said bearings to adjust the position of the ram.

7. In a bending machine, a housing having a side wall, a bearing mounted in said side wall and having a drive shaft journalled therein, a.

beam pivotally mounted on said bearing, a ram,

eccentric means at one end of the beam driven by.

said drive shaft to reciprocate said ram, means on said ram cooperating with said eccentric means and forming a. connection between said housing to prevent longitudinal movementof said,

adjusting screw, andmeans to rotate the adjusting screw to cause the trunnion-nut to raise or lower the beam to adjust the position of the ram. 7

ALBERT RAFTER. 

